Year Percent change 1980 20.3 1981 9.6 1982 15.6 1983 16.735 1984 19.58 1985 11.404 1986 27.953 1987 25.11 1988 9.991 1989 16.653 1990 21.38 1991 20.709 1992 9.744 1993 14.953 1994 6.393 1995 9.725 1996 8.156 1997 4.761 1998 3.378 1999 2.877 2000 2.542 2001 2.231 2002 2.749 2003 4.013 2004 11.709 2005 4.732 2006 7.259 2007 8.571 2008 19.914 2009 9.931 2010 10.58 2011 11.783 2012 7.257 2013 9.754 2014 8.2 2015 11.388 2016 13.969 2017 29.764 2018 14.384 2019 12.753 2020 10.748 2021 7.711 2022 7.24 2023 6.93 2024 7.033